HT1632 Просмотр технического описания (PDF) - Holtek Semiconductor

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HT1632

32x8 & 24x16 LED Driver

Holtek Semiconductor 

HT1632

System Oscillator

The HT1632 system clock is used to generate the time

base clock frequency, LED-driving clock. The clock may

be sourced from an on-chip RC oscillator (256kHz), or

an external clock using the S/W setting. The configura-

tion of the system oscillator is as shown. After the SYS

DIS command is executed, the system clock will stop

and the LED duty cycle generator will turn off. This com-

mand is, however, available only for the on-chip RC os-

cillator. Once the system clock stops, the LED display

will become blank, and the time base will also lose its

function. The LED OFF command is used to turn the

LED duty cycle generator off. After the LED duty cycle

generator switches off by issuing the LED OFF com-

mand, using the SYS DIS command reduces power

consumption, serving as a system power down com-

mand. But if the external clock source is chosen as the

system clock, using the SYS DIS command can neither

turn the oscillator off nor execute the power down mode.

The crystal oscillator option can be applied to connect

an external frequency source to the OSC pin. In this

case, the system fails to enter the power down mode,

similar to the case in the external clock source opera-

tion. At the initial system power on, the HT1632 is in the

SYS DIS state.

O SC

E x te r n a l C lo c k S o u r c e

O n - c h ip R C O s c illa to r

256kH z

S y s te m

C lo c k

System Oscillator Configuration

Name

Command

Code

Function

LED OFF 10000000010X Turn off LED outputs

LED ON 10000000011X Turn on LED outputs

ab=00: N-MOS open

drain output and 8 com-

mon option

ab=01: N-MOS open

drain output and 16

Commons

Option

1000010abXXX

common option

ab=10: P-MOS

open

drain output and 8 com-

mon option

ab=11: P-MOS open

drain output and 16

common option

V DD

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O U T B IT

C u r r e n t- lim itin g

r e s is to r

NMOS Open Drain Driving Mode Configuration

LED Driver

The HT1632 has a 256 (32´8) and 384 (24´16) pattern

LED driver. It can be configured in a 32´8 or 24´16 pat-

tern and common pad N-MOS open drain output or

P-MOS open drain output LED driver using the S/W

configuration. This feature makes the HT1632 suitable

for multiple LED applications. The LED-driving clock is

derived from the system clock. The driving clock fre-

quency is always 256kHz, an on-chip RC oscillator fre-

quency, or an external frequency. The LED

corresponding commands are summarized in the table.

The bold form of 1 0 0, namely 1 0 0, indicates the com-

mand mode ID. If successive commands have been is-

sued, the command mode ID except for the first

command will be omitted. The LED OFF command turns

the LED display off by disabling the LED duty cycle gen-

erator. The LED ON command, on the other hand, turns

the LED display on by enabling the LED duty cycle gen-

erator.

LED Color

Current-limiting Resistor

Red

120W

Green

100W

Recommended Current-limiting Resistor for NMOS

Open Drain Driving Mode

V DD

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C u r r e n t- lim itin g

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PMOS Open Drain Driving Mode Configuration

Rev. 1.00

7

October 2, 2007

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